The Insulin Signaling Core is designed to centralize procedures related to the assessment of key signaling components for each of the projects in this program project. These procedures are integral to the overall hypothesis that insulin signaling plays a major role in the deleterious effect of bedrest or immobilization on glucose or protein metabolism. This facility will provide work to P01 investigators that will not otherwise occur in the individual laboratories, and is, therefore, a critical component of the overall aim of the application. The Insulin Signaling Core will increase the efficiency of data collection and prioritize analyses specific to the needs of each project. This core will also enable us to maintain a higher standard of data interpretation with centralization due to consistent methodological approaches, tissue batching, and reagent processing. The Signaling Core will provide state-of-the-art techniques for projects requesting signaling analyses, with stringent quality control provided for each. To accomplish all these goals, we will pursue four specific aims. Aim 1 will ensure safe processing, shipping, and storage of human and/or rodent muscle tissues for subsequent analyses by the Signaling Core. Aim 2 will conduct RT-PCR analyses of specific mRNA transcripts, focusing on studies related to metformin and fenofibrate administration. In aim 3, we will conduct analyses related to specific signaling intermediates that may be affected by insulin sensitivity, bedrest, pharmacologic intervention with metformin or fenofibrate, or resistance exercise. In Aim 4, we will process samples for investigators at UAMS, when needed, for delivery to the Analytical Core facility at the University of Texas Medical Branch, for subsequent derivitization and/or mass spectrometry analysis.